cleanup sdbus CAMELCASE define

The transition from old camelcase to new camelcase is long completed,
so clean up the old camelcase defines.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ia6443310a0295c55057ab4ce25b39ff89b7b4ecb
diff --git a/nmi_interface.cpp b/nmi_interface.cpp
index f81cecf..a0cafc0 100644
--- a/nmi_interface.cpp
+++ b/nmi_interface.cpp
@@ -35,11 +35,7 @@
     Interface(bus, path), bus(bus), objectPath(path)
 {}
 
-#ifdef SDBUSPP_NEW_CAMELCASE
 void NMI::nmi()
-#else
-void NMI::nMI()
-#endif
 {
     using namespace phosphor::logging;
     using InternalFailure =
diff --git a/nmi_interface.hpp b/nmi_interface.hpp
index d61e8eb..ef871b8 100644
--- a/nmi_interface.hpp
+++ b/nmi_interface.hpp
@@ -33,11 +33,7 @@
 
     /*  @brief trigger stop followed by soft reset.
      */
-#ifdef SDBUSPP_NEW_CAMELCASE
     void nmi() override;
-#else
-    void nMI() override;
-#endif
 
   private:
     /** @brief sdbus handle */